Phacopida

Vietnamia yushanensis

Order Phacopida / Suborder Calymenina / Superfamily Calymenoidea / Family Calymenidae

Katian (Late Ordovician)Jiangxi

Vietnamia yushanensis — photo 1 — Photo 1 · Holotype NIGP152032 (Jiangxi; Lee 2013) Restoration (Lee 2013) Complete dorsal exoskeleton (Jiangxi; Lixia) Literature specimen (Jiangxi; Lee 2013)

Vietnamia yushanensis — photo 2 — Photo 2 · Holotype NIGP152032 (Jiangxi; Lee 2013) Restoration (Lee 2013) Complete dorsal exoskeleton (Jiangxi; Lixia) Literature specimen (Jiangxi; Lee 2013)

Vietnamia yushanensis — photo 3 — Photo 3 · Holotype NIGP152032 (Jiangxi; Lee 2013) Restoration (Lee 2013) Complete dorsal exoskeleton (Jiangxi; Lixia) Literature specimen (Jiangxi; Lee 2013)

Vietnamia yushanensis — photo 4 — Photo 4 · Holotype NIGP152032 (Jiangxi; Lee 2013) Restoration (Lee 2013) Complete dorsal exoskeleton (Jiangxi; Lixia) Literature specimen (Jiangxi; Lee 2013)

Classification

Order Phacopida / Suborder Calymenina / Superfamily Calymenoidea / Family Calymenidae

Genus

Vietnamia Kobayashi, 1960

Genus author

Kobayashi T.

Genus etymology

Vietnam

Species

V. yushanensis Lee, 2013

Species author

Lee D.-C.

Species etymology

Yushan, Yushan County, Jiangxi

Age

Katian (Late Ordovician)

Distribution

Jiangxi

Diagnosis

Dorsal shield long-ovate. Cephalon semicircular; glabella subtriangular with three pairs of glabellar furrows, S1 deep and oblique, S2 short, S3 extremely short; dorsal furrows wide and deep; occipital furrow deep laterally and shallow medially; anterior border slightly arched; eyes small; eye ridges weak; librigenae narrow, without genal spines. Thorax of 13 segments; articulating furrows wide and deep; pleural furrows straight, pleural spines absent. Pygidium triangular; 7 axial rings plus a terminal piece; 5 pairs of pygidial pleural furrows.